[PATCH] D120592: [X86] Preserve redundant Address-Size override prefix

[Amir Ayupov via Phabricator via llvm-commits]

Amir added inline comments.


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Comment at: llvm/test/MC/X86/index-operations.s:74
 stos %rax, (%edi)
-// 64: 	stosq %rax, %es:(%edi) # encoding: [0x48,0x67,0xab]
 // ERR32: only available in 64-bit mode
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craig.topper wrote:
> Was this a bug before? REX prefix is supposed to be the byte before the opcode.
You're right. It was a bug before, but it's still there:
REX prefix emission happened before emitSegmentOverridePrefix and 0x67 prefix, this diff moved 0x67 prefix emission above.
See the line
`    HasREX = emitOpcodePrefix(MemoryOperand, MI, STI, OS);`



Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D120592/new/

https://reviews.llvm.org/D120592